| 摘要 |
PURPOSE:To eliminate waste of the output of an actuator by controlling said output by installing a detection mechanism for detecting a little opened position of a valve departed from the perfectly closed state and a detection mechanism for detecting the position approaching to the perfectly closed state of the valve. CONSTITUTION:When an operation valve 11 is switched to the second position to open a valve 2, the compressed gas flows into the upper chamber 13a of a converter 13 from a flow passage 1, and the valve 2 is driven to the opening direction through an actuator 3. When the first detecting mechanism detects a little opened state of the valve 2, the valve 2 is opened perfectly by the operation of a stopper 3i. Therefore, the output from the actuator 3 is reduced to the value required in case where the necessary driving power for the valve 2 is not so large. When the operating valve 11 is switched to the first position and the operating valve 12 is switched to the second position to close the valve 2, the valve 2 is operated to the closing direction, and when the valve 2 is brought close to the perfectly closed state, a large output from the actuator which is increased to the value required in case where the necessary driving power is large can be obtained. |
